Quantifying maize grain yield losses caused by climate change based on extensive field data across China

Yang

Food and Energy Security

et al. 2022

Self Cite

Improved canopy structure was instrumental in setting maize yield records, and yet it has rarely been examined in China. At Qitai Farm in Xinjiang, we conducted a 4‐year field experiment using China's six highest‐yielding maize hybrids sorted into three yield level groups that were grown at similar growth durations and at optimum densities. The average yield of high‐yield level (HL, 22.3 Mg ha−1) was 7.2% and 24.6% higher than that of medium‐yield level (ML) and low‐yield level (LL), respectively. For each yield level, we measured morphological traits that influence canopy structure and yield. They included plant height, ear height, ear ratio, internode length, leaf numbers, leaf angle, LOV, leaf area, and spatial density of leaf area. Among the preceding morphological traits of the three yield levels, HL’s best optimized the canopy structure, as shown by improved light distribution (19.0% light transmission at the ear) and increased light interception per unit leaf area per day (LIPA, 51.7 MJ m−2 day−1) in the canopy. In comparison, light transmission was 12.2% and 15.9% at the ear and the total LIPAs were 37.2 and 29.0 MJ m−2 day−1 at silking for ML and LL, respectively. HL had significantly longer leaf area duration and a higher photosynthetic rate, especially at the grain filling stage, and its total accumulated biomass at maturity was significantly better (by 13.9%) than LL’s. HL’s harvest index (0.54) was significantly higher than that of ML (0.52) and LL (0.48). HL’s radiation and heat use efficiencies were 2.61% and 1.37 g °C−1 day−1 m−2, both significantly greater than those of ML and LL. Therefore, optimum maize plant types can significantly improve canopy structure and increase resource use efficiency and grain yield.

Section: Introductionmentioning

confidence: 99%

Optimized canopy structure improves maize grain yield and resource use efficiency

Yang

Food and Energy Security

et al. 2022

Self Cite

“…Maize yield formation is determined by grain filling capacity and final grain weight (Zhang et al, 2007b;Chen et al, 2014). Solar radiation is the energy source for photoassimilates (Shi et al, 2013), which are the ultimate driving factor of maize development and growth (Hou et al, 2021). Previous studies concluded that plant growth was more severely inhibited by low light as the level of shading increased (Bidhari et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

“…However, recent studies have revealed that the intensity of photosynthetically active radiation (PAR) reaching the crop canopy is often reduced due to environmental pollution, overcast or rainy, and scant lighting the rainy weather frequently occurs during the crop growing season (Liu et al, 2012;Gao et al, 2017a;Zhang et al, 2019;Poonam et al, 2022). There have been varying degrees of reduction in radiation both nationally and worldwide (Ren et al, 2016;Zhou et al, 2020;Liu et al, 2021d), which could lead to reduced biomass production and maize yield (Hou et al, 2021). The reduction of light availability, especially during grain filling, threatens photosynthesis and carbohydrate synthesis, restricting maize yield (Jia et al, 2007;Zhang et al, 2007b;Ren et al, 2016;Gao et al, 2017aGao et al, , 2020Shao et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Quantitative Relationship Between Solar Radiation and Grain Filling Parameters of Maize

et al. 2022

Self Cite

A quantitative understanding of the factors driving changes in grain filling is essential for effective prioritization of increasing maize yield. Grain filling is a significant stage in maize yield formation. Solar radiation is the energy source for grain filling, which is the ultimate driving factor for final grain weight and grain filling capacity that determine maize yield. Here, we first confirmed the quantitative relationships between grain filling parameters and photosynthetically active radiation (PAR) by conducting field experiments using different shading and plant density conditions and cultivars in 2019 and 2020 in Xinjiang, China. The results showed that with every 100 MJ m−2 increase in PAR, the average grain filling rate (Gave), maximum grain-filling rate (Gmax), and the kernel weight at the time of maximum grain-filling rate (Wmax) increased by 0.073 mg kernel−1 day−1, 0.23 mg kernel−1 day−1, and 0.24 mg kernel−1, and the time of maximum grain-filling rate (Tmax) delayed by 0.91 day. Relative changes in PAR were significantly and positively correlated with relative changes in yield and Gave. With every 1% change in PAR, yield and Gave changed by 1.16 and 0.17%, respectively. From the perspective of grain filling capacity, DH618 was a more shade-resistant cultivar than XY335 and ZD958. It is urgent to breed maize cultivars with low light tolerance and high grain yield in the face of climate change, particularly the decrease in solar radiation.

“…Maize is not only the most productive food crop but also an important source of feed in China, which plays an important role in meeting human dietary needs ( Klopfenstein et al, 2013 ; Hou et al, 2021 ). The water consumption of maize during the whole growth period was relatively large.…”

Section: Introductionmentioning

confidence: 99%

Stable Soil Moisture Improves the Water Use Efficiency of Maize by Alleviating Short-Term Soil Water Stress

Wang

Zhu

et al. 2022

Front. Plant Sci.

Weaker temporal variation of soil moisture can improve crop water use efficiency (WUE), but its physiological mechanism was still unclear. To explore the mechanism, an organized experiment was conducted in Beijing from June to September. From the jointing stage to maturity stage of maize, stable soil moisture (SSM) and fluctuating soil moisture (FSM) were established with Pressure Potential Difference-Crop Initiate Drawing Water (PCI) and manual irrigation (MI), respectively, to explore the physiological mechanism of SSM to improve maize WUE. Among them, PCI treatments were set with 3 pressure differences of -5, -10, and -15 kPa, and MI treatment was watering every 3 days with the irrigation amount of 9.3 mm. The results showed that (1) after water treatment, the average soil water content of PCI-5 kPa, PCI-10 kPa, PCI-15 kPa, and MI treatments were 53% field capacity (FC), 47, 38, and 78% FC, respectively. It was SSM with weak temporal variation under PCI treatments, and FSM with medium temporal variation under MI treatment. (2) PCI treatments reduced the content of proline, malondialdehyde, and abscisic acid in each organ of maize. (3) Compared with FSM 78% FC, the maize root activity at the filling stage of 53% FC SSM and 47% FC SSM increased significantly by 57.1 and 28.6%, respectively, and the carbon isotope discrimination value (Δ13C) in bracts of the two treatments increased by 18.3 and 10.4%, respectively. (4) There was a very significant positive correlation between WUE based on biomass (WUEb) and Δ13C in bracts. In conclusion, a large temporal variation of soil moisture was an important factor that caused water stress in maize. Under SSM treatments, the accumulation of abscisic acid, proline, and malondialdehyde was synergistically reduced. SSM improved the WUE of maize by alleviating short-term soil water stress caused by the fluctuation of soil moisture.